Continuity mistake: When Robin steps foot into Poison Ivy's lair she is laid out on her flower bed. If you look at the sleeves of her costume, the ends of the sleeves are fringed in a simple leaf like design. Robin spurns Poison Ivy's affections, and an enfuriated Ivy pushes him into the lily pad pool. She is then confronted by Batman, and a soon to arrive Batgirl. Now - look at the huge, obvious, black rubber "thorn" bracelets that suddenly appear on each of her wrists. (01:37:25)
Continuity mistake: The first confrontation with Mr. Freeze and his henchman involves them skating around a large ice covered area. The henchman are not using ice skates, but rollerblades. In the same scene we see ice skating blades pop out of Batman and Robin's boots, but when we actually see them skating, they are on rollerblades as well. (00:06:45)
Continuity mistake: In Dr. Woodrue's lab, two thugs carry Antonio Diego over to an experiment table and chain him to it. The thug on Diego's left has a cowboy hat on. However, just as that thug is pulling Diego's mask over Diego's head a few shots later, the thug's cowboy hat is gone. This same thug also disappears from the aerial shots of the lab as Dr. Woodrue is exclaiming over his genius of turning Diego into Bane, a super soldier, with Venom. Later, when Bane breaks free of his restraints, the thug just shows up out of nowhere to try to hold Bane down. (00:16:00)
Continuity mistake: When Dr. Freeze bends down to kiss his wife right before his accident, there is a tube of some sort behind her (in the distance), then as he kisses her the tube is gone. (00:20:15)
Continuity mistake: In the car on the way to the observatory, Pamela Eisley puts on a perfectly straight-haired and slightly red/pink colored wig. But when she is at the observatory, her wig is brown, has numerous fly-aways and has long bits on the sides. (00:32:50 - 00:34:40)
Continuity mistake: As Batman, Robin and Batgirl are heading to the Gotham Observatory to confront Mr. Freeze in their new Bat-Vehicles, a Frostbite piloting Mr. Freeze's Freezemobile meets them, crashing into two cars blocking the Freezemobile's way. The two cars the Freezemobile crashed into are gone in a later aerial shot of the Freezemobile having its freeze ray reflected back at it by Batman's shield.
Continuity mistake: In the first shot that shows a high view of Mr. Freeze standing on the stairs, his ice gun is pointed up. But, when it shows him again, the gun is resting in his hands. The next shot shows him bringing the gun into his hands again. (00:03:50)
Continuity mistake: When Dr. Pamela Isley and Bane first arrive in Gotham City and are driving to the Gotham Observatory in their (stolen) red car, Dr. Isley is putting on a wig. When she grabs the wig out of the box and puts it on her head, you can see that she has black gloves on, but the gloves are missing when she is looking in the mirror and says to Bane "Gotham Observatory, Bane. And step on it." (00:34:05)
Continuity mistake: In one of the scenes when Freeze is going to take the diamonds from Ivy's neck, you can clearly see that he has no make-up in his neck (and it isn´t an effect of the lights, he has really no make-up). (00:45:00)
Continuity mistake: When Bruce and Julie go to the party in the observatory and are swamped by people, in the overhead shot at the start of the scene we can see that Gossip Gerty is trying to get to Bruce and Julie and that there is a man between Gerty and Julie. However, in the next shot (a tighter shot of the couple and onlookers), Gerty is suddenly right next to Julie, in the place where the man had been, with no time for him to move.
Continuity mistake: In the last fight against Bane, Bane has got Robin and Batgirl by their throats against an icy wall. In a close-up of Batgirl, Batgirl's right hand is near Bane's spiked wrist guard. However, in the very next shot, her right hand is more near Bane's elbow.